1 ! Copyright (C) 2008, 2010 Slava Pestov.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: namespaces arrays assocs hashtables kernel accessors fry
4 grouping sorting sets sequences locals
10 compiler.cfg.utilities
11 compiler.cfg.instructions
12 compiler.cfg.predecessors
13 compiler.cfg.gvn.alien
14 compiler.cfg.gvn.avail
15 compiler.cfg.gvn.comparisons
16 compiler.cfg.gvn.graph
18 compiler.cfg.gvn.rewrite
19 compiler.cfg.gvn.slots
21 compiler.cfg.gvn.expressions ;
24 GENERIC: process-instruction ( insn -- insn' )
26 : redundant-instruction ( insn vn -- insn' )
27 [ dst>> ] dip [ swap set-vn ] [ <copy> ] 2bi ;
29 :: useful-instruction ( insn expr -- insn' )
32 vn expr exprs>vns get set-at
33 insn vn vns>insns get set-at
36 : check-redundancy ( insn -- insn' )
37 dup >expr dup exprs>vns get at
38 [ redundant-instruction ] [ useful-instruction ] ?if ;
40 M: insn process-instruction
42 [ process-instruction ]
43 [ dup defs-vregs length 1 = [ check-redundancy ] when ] ?if ;
45 UNION: don't-check-redundancy alien-call-insn ##callback-inputs ;
47 M: don't-check-redundancy process-instruction
48 dup rewrite [ process-instruction ] [ ] ?if ;
50 M: ##copy process-instruction
51 dup [ src>> vreg>vn ] [ dst>> ] bi set-vn ;
53 M: array process-instruction
54 [ process-instruction ] map ;
56 : value-numbering-step ( insns -- insns' )
57 [ process-instruction ] map flatten ;
59 : value-numbering-iteration ( cfg -- )
61 [ value-numbering-step drop ] simple-analysis ;
63 : identify-redundancies ( cfg -- )
65 ! dup compute-avail-sets
69 _ value-numbering-iteration
73 : eliminate-redundancies ( cfg -- )
75 ! dup compute-avail-sets
77 [ value-numbering-step ] simple-optimization ;
81 : value-numbering ( cfg -- cfg )
84 dup compute-avail-sets
86 ! avail-ins get [ [ number>> ] [ keys ] bi* ] assoc-map .
88 dup identify-redundancies
89 dup eliminate-redundancies
91 cfg-changed predecessors-changed ;